Vertical folding shelf

ABSTRACT

A type of foldable shelving rack that includes a folding rack and shelf units. Each level of the folding rack is formed by the hinging together a pair of U-shaped bars. The end of the upper U-shaped bar is hinged to the lower U-shaped bar, thereby forming multiple shelves comprising the foldable shelving unit. A positioning mechanism is located on the opposing hinged ends of the quadrilateral structure; each shelf unit rests between the middle sections of the two U-shaped bars, thus forming a stable and integrated unit that can be folded up.

CROSS REFERENCE TO PREVIOUS APPLICATION

This application is a continuation in part of U.S. patent application Ser. No. 15/489,913, filed Apr. 18, 2017, which application is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

This invention is to a type of foldable shelving rack, which is specifically has a strong stability while maintaining the ability to be folded vertically.

Technical Background

Currently, there are multiple different models of foldable shelving racks, but most are difficult to open and unfold and they have poor stability. For instance, Chinese Patent Publication Application No. 201520384604.0 consists of a folding book storage device, having separators, a rack and an armrest. It has multiple levels of separators, with both sides of each separating board being supported by crossing tubular rods making up the rack structure. This rack structure's crossing rods are connected by hinges, thus allowing the storage device to expand and contract and well as being folded up for storage. However, it does not describe how the two sides of this rack are connected or how the separating boards fit into the structure.

Another example is Chinese Application No. 201521014461.0, which consists of a foldable shoe unit with folding racks arranged parallel to each other and with a number of laminated shoe frames located at corresponding positions between these folding racks. The folding racks are further equipped with a cross piece to help sustain the shoe frames. The left side of each shoe frame is connected to the folding rack by means of a rotating shaft and on the right side, a panel is placed at the crossing section, all of which serves to provide support and stability for the unit. Folding it would require every shoe frame to be turned over, and during the folding process the shoe frames would be hanging at one end, thereby posing a potential hazard. Furthermore, the two ends of the folding frame rely on right-side hinges to secure the connection, thereby weakening the stability.

The objective of this invention is therefore to overcome current technological shortcomings and to provide a foldable shelving rack with proper stability.

SUMMARY OF THE INVENTION

The purpose of this invention is to provide a type of foldable shelving rack where each level is cross-hinged by a pair of U-shaped bars, with the upper U-shaped bar being hinged to the lower U-shaped bar, thereby forming multiple shelves comprising the foldable shelving unit.

The technical plan of this invention was accomplished is part by the following:

A type of foldable shelving rack that includes foldable trays and shelving units.

The foldable rack has a multilevel structure, with each level having a shelving unit; it has the following special features:

Each level of the folding rack is formed by the hinging together a pair of U-shaped bars.

The above-mentioned U-shaped bars have a middle section and two parallel curved sections. The pair of U-shaped bars on each level help the curved sections to hinge together.

The end of the upper U-shaped bar is hinged to the lower U-shaped bar, thereby forming multiple shelves comprising the foldable shelving unit.

A positioning mechanism is located between opposing hinging points of the quadrangle structures on each side of the folding rack.

The shelves are placed between the middle sections of two U-shaped bars and are supported by the middle sections of the U-shaped bars.

There is a pair of U-shaped bars on the bottom level of the foldable rack, with the two parallel curved sections connected by bars, and a narrow shelving unit resting on the two connecting bars.

The two sides of the above-stated narrow shelving unit have a downward-facing curved edge. This curved edge is longer than the semi-circular shape of the connecting bar, and secures into position by attaching onto the connecting bar.

Handles are located on the middle sections of both ends of the above-stated narrow shelving unit.

The shelving units consist of metal trays with extended edges on two sides allowing for the tray edges to rest on the middle sections of the U-shaped bars. Handles extend from the middle section of the two ends; the metal trays can be constructed in any of the following ways: a steel-wire tray, a woven steel tray, or a standard basket.

The above-stated positioning mechanism comprises a working piece with a grip and a fixed piece. On one end, the working piece is hinged at the hinge point of the quadrangle structure. In the middle, the hinged piece is hinged onto the fixed piece and the other end of the working piece has a protrusion near the grip that is used for locking. On the one end, the fixed piece is hinged onto the opposing hinge of the quadrangle structure. On the other end, it is hinged to the working piece, as mentioned above. The middle part of the fixed piece is provided with a hole corresponding to the protrusion located on the working piece. When the shelving unit is in open position, the grip is pushed and the protrusion on the working piece slides into the hole, forming a lock.

The above-stated positioning mechanisms are attached in a vertical position. The moving pieces hinge to the upper sections of the quadrangle structures, while the fixed pieces hinge at the lower sections of the quadrangle structure.

The above-stated positioning mechanism is a rigid latch or a hinge. One end of the rigid latch or hinge connects to the horizontal hinge of the quadrangle structure, whereas the other end has a clip, which can connect to the diagonal hinge of the quadrangle structure, thereby providing stability.

Each of the level of the foldable shelving unit is constructed with a pair of cross-hinged U-shaped bars, which serve a dual purpose of supporting the shelf as it can rest on the middle sections of the bars and also connecting on each end to the rack itself, which provides stability for the structure. Furthermore, the upper U-shaped bars are hinged to the ends of the lower U-shaped bars, forming a quadrangle four-bar linkage mechanism to achieve a vertical opening and folding function. The key features of this invention include being simple in structure, reliable in support and stability, and easy to operate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is to the general perspective view of the shelving rack

FIG. 2 is a side view of the shelving rack

FIG. 3 is an exploded view of the shelving rack

FIG. 4 is a view of the shelving rack in a folded position

FIG. 5 is a side view of the shelving rack in a folded position

FIG. 6 is a view of a positioning mechanism for use with the shelving rack.

Similar reference characters denote corresponding features consistently throughout the attached drawings. Namely, in the drawings the following reference numbers refer to the following part:

-   1—U-shaped bar -   11—middle section -   12—curved section -   13—connecting bar -   100—Folding rack -   2—shelf unit -   21—tray edge -   22—handle -   23—curved edge -   24—clip -   201—narrow shelving unit -   202—working table top -   3—working piece -   31—protrusion -   32—grip -   4—fixed piece -   41—hole -   5—rigid latch -   51—clip

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIGS. 1 to 4, the foldable shelving rack is composed of the folding rack (100) and shelf units (2). The folding rack (100) has multiple levels, with each level holing one shelf unit (2). There is also a narrow shelving unit (201) near the ground at the bottom of folding rack (100). The folding rack (100) can also be fitted with a working table top (202) to replace a shelving unit (2). This working table top can be set at a height suited to the comfort of any particular user.

As shown in FIG. 3, within the multilevel structure of folding rack (100), one of the shelf levels can be fitted with the working table top (202). Each level is formed by the hinging of a pair of U-shaped bars (1). The U-shaped bars (1) has a middle section (11) and two curved sections (12) set parallel to each other. The U-shaped bar (1) is then cross-hinged by the curved sections (12). Each level forms a separate stable unit. The curved sections (12) of the upper U-shaped bars (1) connect to the curved sections (12) of U-shaped bars (1) at the next level down, which serves to form a quadrangle structure that provides support and vertical folding functions. Because the two sides are connected by the middle sections (11) of the U-shaped bars, and particularly because of the integrated nature of the U-shaped bars, this then creates heightened stability for the multi-level foldable rack (100). Even without the shelf units (2) in place, the rack structure remains stable independently. It can also conveniently be used for storing a variety of objects.

Each shelf unit (2) rests between the middle sections (11) of the U-shaped bar. Each shelf unit (2) is then supported by the middle sections (11) of U-shaped bars. Each shelf unit (2) consists of a metal tray. Two sides of the metal tray have an extended tray edge (21). The tray edge (21) rests on the middle section (11) of the U-shaped bar, with the bottom portion of the metal tray set into position on two middle sections (11). The center portion of the two ends of each metal tray has a handle (22) that extends outwardly, which allows for easy lifting of the shelf unit (2) with both hands. The metal trays can be constructed in any of the following ways: a steel-wire tray, a woven steel tray, or a standard basket.

On small shelving racks, the shelf units (2) can merely consist of molded plastic baskets. Because folding rack (100) is an independently stable structure, it does not require the shelf units (2) for additional stability. This greatly simplifies the design of the two corresponding units, thereby allowing the structure and style of the shelf units (2) to be designed with more versatility, or allowing for other items such as flat boards to be substituted instead.

There are connecting bars (13) located between the two parallel curved sections (12) of the pair of U-shaped bars (1) on the bottom level of the folding rack (100). A narrow shelving unit (201) rests onto these two connecting bars (13). This helps in not only utilizing the space near the ground, but also stabilizing the chassis of folding rack (100) and help to maintain the center of gravity. The two sides of the above-stated narrow shelving unit (201) have a downward-facing curved edge (23). This curved edge (23) is longer than the semi-circular shape of the connecting bar (13), and secures into position by attaching onto the connecting bar (13), thereby creating stability. This also helps to ensure that the gap between the curve sections (12) of the two ground-touching lowest level U-shaped bars is consistent, and the bottom level of the structure is more stable.

The narrow shelving unit (201) and the shelf units (2) are composed of similar materials and a similar structure, with both ends of every unit having handles (22) extending outward. Additionally, the narrow shelving unit (201) can be easily placed into a shelving unit (2) on any level and does not take up any space after folding.

As shown in FIG. 3 and FIG. 4, the optional working table top (202) is equipped with clips on the underside, which can be attached onto the middle sections (11) of the corresponding U-shaped bars, thereby creating a working table top (202) that is stable, slip-free, and meets the operating needs of the user. In designing this rack, packaging requirements were also considered. The width of working table top (202) is less than the distance between the middle sections (11) of the two U-shaped rods after the folding rack (100) has been folded. The working table top (202) can therefore be stored without occupying any additional space.

Because the other shelf units (2) can be stacked on top of each other, and narrow shelving unit (201) can rest on top of the shelf units (2) to form a stack, all of them can therefore be stored in the interior space of the folding rack (100) after it has been folded up. The resulting overall dimensions are therefore small, making storage and transporting convenient.

As shown in FIG. 2 and FIG. 5, there is a positioning mechanism located between opposing hinging points of the quadrangle structures on each side of the folding rack (100). They serve to lock the foldable shelving rack into its designated open position. As shown in the figures, the positioning mechanism comprises a working piece (3) with a grip (32) and a fixed piece (4). On one end, the working piece (3) is hinged at the hinge point of the quadrangle structure. In the middle, the hinged piece is hinged onto the fixed piece (4) and the other end of the working piece has a protrusion (31) near the grip that is used for locking. On the one end, the fixed piece (4) is hinged onto the opposing hinge of the quadrangle structure. On the other end, it is hinged to the working piece (3), as mentioned above. The middle part of the fixed piece is provided with a hole (41) corresponding to the protrusion located on the working piece. When the shelving unit is in open position, the grip (32) is pushed and the protrusion (31) on the working piece slides into the hole (41), forming a lock. In order to ensure the reliability of the locking function of the latch, the moving piece (3) interacts slightly with the fixed piece (4), and makes use of the grip (32) located on the fixed piece (4) to create interference during locking. This has the benefit of creating even more support as more weight or pressure is applied, which can help to prevent accidents stemming from the latch being inadvertently opened. The mechanism can be operated in reverse by pulling the grip (32) outward around the interference point. Gravity will then pull the folding rack down layer by layer, and the moving piece (3) and fixed piece (4) will also stack together and will not occupy extra space.

As shown in FIG. 6, in addition to what is described above, the positioning mechanism can also consist of a rigid latch (5) or a hinge. One end of the rigid latch (5) or hinge connects to the horizontal hinging point of the quadrangle structure, and the other end has a clip (51) that attaches onto the opposing hinge of the quadrangle structure. Both of these options can serve the purpose of positioning, although the operational procedures are slightly different. 

1. (canceled)
 2. The foldable shelving rack of claim 9, wherein there is a pair of U-shaped bars on the bottom level of the foldable rack, with the two parallel curved sections connected by bars, and a narrow shelving unit resting on the two connecting bars.
 3. The foldable shelving rack of claim 2, wherein the two sides of the narrow shelving unit have a downward-facing curved edge; where this curved edge is longer than the semi-circular shape of the connecting bar, and secures into position by attaching onto the connecting bar.
 4. The foldable shelving rack of claim 3, wherein a number of handles are located on the middle sections of both ends of the above-stated narrow shelving unit.
 5. The foldable shelving rack of claim 9, wherein the shelving units consist of metal trays with extended edges on two sides allowing for the tray edges to rest on the middle sections of the U-shaped bars; a number of handles extend from the middle section of the two ends; and the metal trays are constructed in any of one of the group of a steel-wire tray, a woven steel tray, or a standard basket.
 6. The foldable shelving rack of claim 9, wherein: the positioning mechanism comprises a working piece with a grip and a fixed piece; on one end, the working piece is hinged at the hinge point of the quadrangle structure; in the middle, the hinged piece is hinged onto the fixed piece and the other end of the working piece has a protrusion near the grip that is used for locking on the one end, the fixed piece is hinged onto the opposing hinge of the quadrangle structure, on the other end, it is hinged to the working piece, as mentioned above; the middle part of the fixed piece is provided with a hole corresponding to the protrusion located on the working piece; and when the shelving unit is in open position, the grip is pushed and the protrusion on the working piece slides into the hole, forming a lock.
 7. The foldable shelving rack of claim 9, wherein the positioning mechanism is attached in a vertical position.
 8. The foldable shelving rack of claim 1, wherein the positioning mechanism is a rigid latch or a hinge.
 9. A foldable shelving rack that includes a folding rack and shelf units; the shelving rack has a multilevel structure, with each level holding a removable shelf unit; wherein each level of the folding rack is formed by the hinging together a symmetric pair of U-shaped bars; said U-shaped bars each having a middle section between two opposing, parallel sections; each parallel section of an upper level U-shaped bar is rotatingly connected directly to a portion of the parallel sections of a lower level U-shaped bar below the upper level U-shaped bar at a connection point, thereby forming the multiple shelves of the foldable shelving unit; a positioning mechanism is connected from the hinge on the upper level U-shaped bar and the hinge on the lower level U-shaped bar or is connected between the connection points of the lower level U-shaped bar, wherein when said positioning mechanism is in a first position, the hinge of the upper level U-shaped bar is fixed in position relative to said lower level U-shaped bar hinge and when said positioning mechanism is in a second position the upper level U-shaped bar hinge can move relative to said the lower level U-shaped bar hinge; and a removable shelf unit is connected on each level by placing the respective shelf on top of a pair of the U-shaped bars' middle sections for each level.
 10. The foldable shelf of claim 9, wherein distance between the upper level U-shaped bar connection points is narrower than a width of a shelf mounted to the upper level U-shaped bar.
 11. The foldable shelf of claim 9, wherein on each level, one parallel section of the upper level U-shaped bar connection points is inside of one parallel section of the lower level U-shaped bar, and one parallel section of the upper level U-shaped bar connection points is outside of one parallel section of the lower level U-shaped bar.
 12. A foldable shelving rack that includes a folding rack and shelf units; the shelving rack has a multilevel structure, with each level holding a removable shelf unit; wherein each level of the folding rack is formed by the hinging together a symmetric pair of U-shaped bars; said U-shaped bars each having a middle section between two opposing, parallel sections; each end of an upper level U-shaped bar is rotatingly connected at the end of the parallel sections to a lower level U-shaped bar below the upper level U-shaped bar at a connection point, thereby forming the multiple shelves of the foldable shelving unit; a positioning mechanism is connected between the connection points of the lower level U-shaped bar; wherein when said positioning mechanism is in a first position, the hinge of the upper level U-shaped bar is fixed in position relative to said lower level U-shaped bar hinge and when said positioning mechanism is in a second position the upper level U-shaped bar hinge can move relative to said the lower level U-shaped bar hinge; and a removable shelf unit is connected on each level by placing the respective shelf on top of a pair of the U-shaped bars' middle sections for each level. 